Ophthalmological instrument



y 1931- I c. L. HUNSICKER 1,804,691

OPHTHALMOLOG-ICAL INSTRUMENT Filed May 4, 1927 3 Sheets-Sheet 1 1N VEN TOR C(yde L fi l/"sicker May 12, 1931. c. L. HUNSICKER OPHTHALMOLOGICAL INSTRUMENT a Shee ts-Sheet 2 Filed May 4, 1927 I k m 0 WW TH A W2 .5 We m d my May 12, 1931. c. L. HUNSICKER 1,304,691

OPHTHALMOLOGICAL INSTRUMENT Filed May 4, 1927 s Sheets-Sheet 3 H 144 iL I a9 88 57 91 63 31985 a: 94 A4 74 75 /24 /9 2/ I INVENTOR C(yae 1.. hu/v/cker J13 ATTORNEYS patented May 12 1931 UNITE sires:

CLYDE L. HUNSIGKER, SAN FRANCISCO, CALIFORNIA.

OPHTHALMOLOGICAL INSTRUMENT Application filed May 4,

'lhisinvention relates generally to optical instruments commonly known as optometers, which are used in testing eyes in order to determine the correct value of corrective lenses; It relates particularly to optometers of the type in which a plurality of lenses are mounted within a casing and are adapted to be controlled by an operatorto secure different refractivepowers.

It is an obj e'ct'of this invention to generally improve upon: the construction of optometers andto producea compact convenient instrument of this kind which will facilitate making accurate prescriptions for the eyes in as minimum of: time.

It is a further object of this invention to devise an optometer which will have such a wide range of refractive power that it may be used in practically all cases of eye test- 2K). ing 1 It is a further object of this invention to minimize the time necessary to. adjust an optometer by providing selecting means for moving a major lens carrying member inderange of equivalents consistent with the state of the prior art.

Rei errlng'to the drawings :1

Figure 1 is a front elevational view. of acomplete instrument embodying the invention, certain partsbeing broken away.

F igi 2'is a section taken along the line 2-2- ofFig; 8 and showing the drive for the means for indicating'the axiali relationship of the cylindrical gears.

pendentlyof a minor lens carrying member,.. in addition to a mechanical connection be the appended claims arev to be accorded av 1927. Serial No. 188,734.

Fig. 3- is a section taken along the line 3'-3 of Fig 8 and showing the planetary. gear drive for the cylindrical lenses;

Fig; 4 is a section taken along theline H ofFig. 8 showing the minor lens: carrying y, member. i r

5 is a section taken along the line=5:-:-5' of- Fig; 8 showing the major lens carrying member. 1 V

Fig: Sis a section taken along the line 66 of F 8,showing the rear side of themajor lens carrying member, parts being broken. away. I

Fig. 7 is a section taken along theline '7 '-7 f of" Fig. 8' showing the intermittent movement for mechanically connecting the minor and major lenscarrying members;

Fig. 8 is a transverse cross section take along the line 88 of Fig. 1.

Fig. 9'is a transverse cross SGCtlOl'lELli view taken along the line 9-9 of Fig. 1-.

Fig. 10 is a detail section taken along the- .line 10'10 of Fig. 5. e i

The invention may be outlined'generally as comprising a pair of lens holding devices, onez device being supplied for each eye of the patient. The construction of each ofthese devices includes acasing having anopening therethrough for passage of light, within which casing there is disposed a plurality of I movable lens carrying members. Spherical lenses of different powers are mounted on 'at least two of these'members and are spaced: circumferentially thereon so that they may be brought into individual registry with the casing opening. The spherical lenses onone of these members are graded finelyand have been termed minor lenses in the subsequent description, while the lenses of the other mem her are graded'coarsely and'havebeen termed major lenses. A mechanical connection is:

provided between the two; spherical lens carrying members so that when one member has been mechanically rotated to bring all of its lenses into successive registry with the opening, the major lenscarrying member is moved annularly a suflicient distance to'bring,

the next major lens into registry with the opening; As" an important featureoff this invention, means is; provided; forrdisengaging;

7 this mechanical connection so that the major lens holding member may be selectively oscillated to any desired positi'onso as to secure the approximate refractive power without the necessity of moving the minor lens carrying member. The cylindrical lenses of different powers are disposed in spaced relationship upon a third rotatable member and are adapted to be brought into successive registry with the casing opening, and if desired, they may be superposed with spherical lenses. An adjustment is also provided so that these cylindrical lenses may be rotated about their axis when in registry with the opening. A special feature of this adjustment is that it does not rotate all of the lenses simultaneously, but only those lenses which are adjacent to the casing opening.

Referring to the drawing for a more complete description, there is showna pair of lens holding devices 11 which are supported by means of an adjustable bracket 12. These devices are identical and each include a casing made up of spaced front and back plates 13 and 14 between which the lens carrying members and mechanism are mounted. These platesare provided with alined apertures 16 so as to form a clear opening 17 extending through the casing, and the various lenses are adapted to be brought into registry with this opening. For attaching the casing to the bracket 12, the plates 13 and-14 are provided with aperture tabs 18 and 19 through which extend the bolt 21. Bolt 21 is provided with an extension rod 22 which is attached to the depending arms 23 of the adjustable bracket 12. These arms are adjusted lateral- 'ly by having the same connected to racks 24 which engage a pinion 26 ,this pinion being manually rotated by means of the knob 27 The racks 24 and arms 23 are pivotally mounted to a support member 28 so as to be rotatable about a horizontal axis alined with the axis of the pinion" 26. The racks 24 are-slidably mounted upon anarm 29 which is adjustable with respect to the support 7 means of a setscrew 31. A suitable level gauge 32 is mounted upon arm 29, so that an operatormay readily adjust the devices 11 to the same level by adjusting the screw 31. 1 As has been previously explained there are two lens systems mounted within the casing of each device, one system being cylindrical and the other spherical. lVhile these systems are brought into co-operative relationship with each other, they maybe separately described.

' vyl'indfical Zens system The central portions of the two plates 13 and 14 are. retained together by means of a bolt 34 which is retained in place by means of the removable capscrcw 36. Disposed within the casing adjacent the inner face of the top plate '13, there is a lens carrying member 37 which is preferably rotatably mounted on member 28, as by an axis concentric with the bolt 34. A plurality of cylindrical lenses 38 of graded powers, are spaced around the face of disc 37 and are adapted to he brought into registry with opening 17 The mounting for these lenses whereby they may be individually rotated independently of disc 37, will be presently described.

For manually rotating the lens carrying member 37, there provided a gear 41 which is arranged externally of the front casing plate 13, and which is tired with respect to member by means of screws 42 and dowel pins Rotatably mounted upon the front face of plate 13, there is a control knob 44 carrying a pinion 46 adapted to mesh with the gear 41. Knob 44 is also provided with a circular i ember 47 which is provided with a plurality of circumferentially spaced notches 48 adapted to be engaged by a spring pressed detent 49. The driving ratio between pinion 46 and gear 41 is such that the detent 49'engages a notch whenever a cylindrical lens becomes alined with the aperture 17.

In order to individually rotate the cyiindrical lenses, I have provided aplanetary gear mechanism, which however diifers from the ordinary planetary gears provided on such instruments in that when an alined lens is being rotated, the majority of the other lenses remain relatively stationary. Referring now to Figs. 3 and 4, it will be observed that the individual cylindrical lenses are mounted within ring or sun gears 51 which are journaled within the lens carr ing member, and are provided with external gear teeth. Journaled concentrically with respect to the lens carrying member 37, and disposed between this member and the front casing plate 13, there is a center gear 53 having its periphery formed with a blank portion 54, and a segmental toothed portion 56. Each of the rings 51 is also provided with atoothed periph- V member 37, as they pass the toothed segmen tal portion 56. However in moving about the remainder of center gear 53, they remain relatively stationary with respect to the member 37. Likewise if the center gear 53 is rotated while the lens carrying member 37 remains stationary, the majority of the ring gears 51 remain stationary while those gears adjacent to the aperture 16 are rotated about their axes; Suiiicient teeth are provided in the segmental portion 56 so that the gear of plate 13.

ring which is registered. with. the opening 17', may be rotated through. an angle otlat.

least 180 degrees. Rotation. of the center gear 53 is effected: by means'of. a control knob 59 which is rotatably mounted upon the front.

plate 13. This knob carries a pinion 61 which meshes with a gear segment 62. This gear segment 62 is preferably disposed between.

the gear 41 and the face of-plate' 13, and: is fixedwith respect to centergear 53. as by means of screws 63.

In order to provide visual means for indicating the angular position of the axis of a. cylindrical lens being employed, suitable means is provided which includes a. tube 64 which is journaled within the aperture 16 carries a pinion 66 which meshes with: the center gear53. An indicating scale thereis a pointer 68 which is secured to the outer portion oftube 64. If desired an additional.

lens may be inserted in tube 64, and for this purpose I have shown in Fig. 8 an additional lens 69 which is mounted within a sleeve 70,

this sleeve having tabs 71 which. serve to re movably lock the sleeve within tube 64.

Tabs 71 may engagebeneath the projecting portions 72 and 7 3 carried by. tube 64.

Spherical. lens system Disposed between the rotatable member 37 and the back plate 14,. are the two superposed disc-like rotatable members 74 and 75. The member 74 carries a plurality of finely graded 1 spherical lenses 76, which'will be subsequently referred to as minor lenses, and member to'as major lenses. In'practice a sufficiently fine variation in lens power can be obtained by having successive minor lenses differed by about .25 diopters, and all of they minor lenses may be positive. The difference in powers between successive lenses of the member 7 5- will depend upon the-number of minor lenses provided. For every complete revolutionof the minor lens holding member, the ma or lens carrying member is intended to be moved an angular distance sufficient to bring. the

. next major lens in registry with the casing opening. Therefore to maintain an even gradinginlrefractive power the difference between successive major lenses should be substantially equal to the difference betweenthe .weakest and strongest lens of the minor'series plus twice the difference between successive lenses of the minor series. For example in the specific instance illustrated in which sixteen lenses have been provided in the minor series ranging from .25 diopters to 4.00 diopters, the difference between successive lenses of the major series is 4.25 diopters. Both a positive. anda negative reading of refractory power may be secured by providing both positive-and negative ma or lenses. For

The inner portion of tube 64,

5 carries a plurality of coarsely graded lenses 7 7 which will be subsequently referred example int this; specific: instance the .major lens powe zs run. from zero to 25.7 5 diopters and likewise fromzero to 17.0 diopters..

The members 7 4 and 75 are mountedso as toturn about. thep'in. 34,. the member 74 being journaleddirectly upon. pin 34 and having a hub. portion 81. which extends through the gear 41 previously described, and forms a. journal forthis gear. The drive mechanism or mechanical connection imposed between; member 74 and 75. preferably includes an in:-- termittent motion gear drive. For example. asshown in Figs..7 and 9 there is providedian element82 which is ournaled upon a projectingboss 83 provided upon the member 74. An angular ring 84, secured. to one face of element 82, forms a journal for the rotatable member? 5. The'element 82 carries a projecting pin or tooth 86'which engages and effects intermittent motion of the'slotted wheel 87. Since the wheel 87 isprovided with four slots and there isonly one toot-h upon the rotatable element 82, for every completerevolution of element 82, the wheel 87 is rotated one quarter turn. lVheel 87 is suitably journaled upon a pin 88 projecting inwardly from the back plate 14, and carries a pinion 89 which meshes with a gear 91, gear 91 being imposed be tween the member 75 and the element 82. Since thewheel 82'is fixed with respect to the member 7 4, rotation of this member causes intermittent rotation of the slotted wheel 87 which because of pinion 89'and gear 91 causes intermittent rotation of gear 91.

A connection is provided between gear 91 and the movable me1nber75 but this connec-,

tion is disengageable so as to permit movesiliently urged into lockingengagement as bymeans ofa spring 97. Normally the locking bar 96 projects beyond the periphery of'the instrument and is provided witha finger hold portion 98 which is adapted to be moved outwardly by the operator to withdraw the locking bar 96. The finger hold portion 98 is preferably in the form of a lever pivotally secured to the outer end of locking bar 96 as by means of pin 99, the other end of the lever beingprovided with the lugs 101 which are normally disposed adjacent. the peripheral.v

portion103-of the back plate 14. Spring 100 tends to resiliently urge the member 98 outwardly about; its pivot.v l/Vhen the finger hold; portion 98 ismoved outwardly, it may be oscillated relative to the. casing, carrying;

Jlens carrying member between that member and the member 741.,

with; it the major lens holding inemberindependently of the minor lens holding member. In other words by means of this disencome disengaged when the major lens holding member is in this position. To reengage the locking bar, it is only necessary to swing the finger hold portion 98 against the tension of spring 100 until the lugs 101 are disengaged from cam portion 10 1. Lugs 10]; snap back in position after the locking bar has been moved away from portion 10 Thus referring to Figs. 8 and 9, if the major lens holding member 7 5 is turned manually to the limit of its movement in a clockwise direction, the cam surface 10 1 causes disengagement of the locking bar 96 so that the minor lens carrying member 7 1 may thereafter be rotated independently.

Rotation of the lens holding member 7 1 'may be conveniently efl'ect'ed by means of a knurled finger hold portion 106 whichis exposed at the edges of the casing. is has been previously explained. for every complete revolution of member 7 4: member 75 is moved an annular distance suiiicient to bring anew opening is secured by the use of the spring pressed detents and 107 which are mounted within a member 108 secured to the back plate 14, which detents press against the respective peripheries of member 7 4 and 7.). Notches 109 and 111 are provided in the peripheries of members 741 and 7 5 and are spaced so that when engaged by the detents 105 and 107, the lens carrying members are retained in the desired position. These detents also prevent direct turning of the major The member 108 serves as a stopfor limiting movement of the major lens holding member in one direction, while a pin 112 arrests movement in the other direction. The peipheral portion 103 of the back plate has been marked at spaced points with numbers corresponding to the different positions of the finger hold member 98. Asshown in Fig. 1, the lens powers increase positively as the finger hold portion 98 is rotated in a counterclockwise direction until maximum positive power is reached, which in this instance is 17.00 diopters. The other limit of member 98 is also a position of zero power and as the 75, through friction member is rotated from this position in a". clockwise direction, the lens powers decrease negatively from zero to -29.75 diopters. By means ofthisarrangement a gradual grading of lens powers may be obtained in the positive direction by rotating the minor lens carrying member in a counterclockwise direction, and a gradual increase in negative refractory power may be secured by rotating the minor lens carrying member in a clockwise direction, assuming of course that the member 98 has been moved to one of the negative positions.

As explained above, the lens powers are graded finely on member 7 1 and coarsely on member 75. As it is necessary to have a po sition of Zero power for the device, member 741 has been provided with a blank space 76a and member 7 5 with two blank spaces 77 a. Likewise a blank space 38a is provided on the spherical lens carrying member 37. Therefore both limits of movement of major lens carrying member 75 are zero lens power positions. With all the lens carrying members set to zero position, a complete rotation of member 7st may be effected before the lowest power lens of the major series is brought into registry with the casing opening and the blank space of member 74:.

-t will be noted that the distances between successive notches 109 on the member 74 are not all the same. One space a is substantially longer than the others. It is this space which is passing by detent 105 when movement of member 7 4t carries with it the major lens carrying member 7 5, and when the zero lens of member 75 is coming into registry with opening 75. Therefore when an operator is turning the member 7 1, he can tell by feel when zero position of this member is reached, and can therefore keep a check upon the approximate refractive power being used without referring to the indicating graduations. Another advantage of this construction is that it permits a greater gear ratio between pinion 89 and gear 91, thus making it easier to turn member 7-1 when member 7 5 is being shifted to a new position. It also provides for a certain amount of overthrow to take care ofwear.

In order to indicate the exact refractive power of a spherical lens combination, the front plate 13 is provided with a window or opening 113 through which a portion of the face of the minor lens holding member may be viewed. Unobstructed View of the spherical lens holdin members may be secured by providing a series of apertures 11 1 in the cylindrical lens carrying member 37. Likewise an arcuate slot 116 is provided in the center gear 53. The minor lens carrying member is provided with a series of smallerapertures 117 which comeinto alinement with the window 113 for the positions of registry for the lenses of this member. Fig

*ures ll8-stampedalong the edges of apertures 117 are visible through the window 113,.and

indicate the refractory power of the particular minor lens which is almed with the casingopening. 'ilhe minor lens carrying mem ber 75 is provided with markings 119, which may supplement the markings upon the periphery of the back plate 14. The markings 119 are adapted to register with the openings 11 and the particular marking visible through "window 113 indicates. the refractory power of that major lens which is alined of one of the lens "holding devices, or may be moved to provide a pin hole for adjusting the-devices to the correct papillary distance. This screen 124 is shown in Figs; Sand 9 and isdisposed within a recess provided ing or pin hole.

upon the inner face of back plate 14. As

shown in Fig. 7 it is provided with a pin hole 126 and a clear opening 127. The screen is arcuate in shape and is rotated asby means of a lever 128 which extends beyond the periphery of the casing. Suitable detents 129 are provided so as to properly aline the open- Opera-tion The operation of the device may be outlined asfollows': Diiferent powers 'of cylindrical lenses are secured by rotation of the control knob 44. which effects rotation of the cylindrical. lens gholding member 13. To

effect axial rotation of a particular lens, the

operator rotates knob 59 which effects rota-' tion of the center gear 53 which meshes with the ring gears 51.

Pointer 68 is rotated simu'ltaneously with rotationof an alined lens and indicates theangular positioniof the lens axis. if the operatorhas an approximate idea of the refractive power of the spherical lens required, the member 98 is engaged and the major lens holding member is quickly shifted to the a'pproximate'lens power as in dicated by the markings upon the periphery 103. The minor lens 'holding member 74: is then rotated by engaging the peripheral portion 106, until the refractory power is graded to' the exact value desired. If the minor lens holding member 74 is rotated suficiently far, the drive connection provided between the spherical lens holding members causes the I major lens holding member 74 to be shifted an annular distance sufiicient to bringa new 7 power required.

major lens -:intoalinem ent with the casing opening. If member 98 i'sin position'to secure positive refraction, the minor lens carrying member is rotated in acounterclockwise direction to increase the refractory powerof the spherical lens combination, while if member 98 isin a position to secure negative refraction, it is rotated inma clockwise direction tosecure an increaseneg atively in refractory power. The refractory power of the cylindrical lens system is read through the window: or opening 121, while that ofthe soherical system is read through opening-113. i

l ()ne of the most important features of this invention :is the ease and rapidity which the spherical lens'systein may be adjusted for different refractory powers. The operator usually has an idea of the approximate lens exact value. The particular form of cylindrical lens .systenidescribed is desirable as it requires practically no power to operate,-

since only a small number of the ring or sun gears are rotated upon movement of the center gear. If all of the ring gears were rotate-d upon rotation .of the center gear, :the excessive wear would result in 'posslbleinac-r curacies. In practically all cases sufiicient refractive power may be obtained by merely su eriosin the sjherical and c lindrical lensesprovided. In case additional refractive power is desired, t may be secured by introducing thesupplemental lens. It is to be also noted that the back plate is facingrthe patient and thattherefore the major lenses are the nearest to the eye. It has been found that this arrangement which places the strongest lens nearest the eye of the patient, gives'more accurate results in eye testing and decreases inaccuracies dueto telescoping effect. In the adjustment of the device to increase or decrease the refractive power,

no sudden changes in lenspower occur and 'zero power'position cannot be reached suddenly by adjustment of the minor lens carrying member 74. 7

tie of the device reduces the possibility of This inherent characteriserrors in determining the accommodative scope of the eyes.

I claim: f

1.111 a device of'the class described, a movable member carrying a plurality of minor lenses, another movable member carrying a plurality of major lenses, meansmechanically connecting said members whereby upon movement of one of'saifd members, any one'major lens maybe superposed with any one minor T lens upon movement of one ofsaid members, and means for disengagingsaid mechanical connection." I 1 52. In a device of the class described, a mcvable-member carrying a plurality of lllll'lOI The. member 98 is 'set to I this approximate power and then the minor lens holding member adjusted to secure the lenses, another movable member carrying a plurality of major lenses, means mechanically connecting said members whereby upon movement of one of said members, any one major lens may be superposed with any one of said minor lenses, and means for eifecting manual movement of one of said members independent of said other nember.

3. In a device of the class described, a movable member carrying a plurality of minor lenses, another movable member carrying a plurality of major lenses, means mechanically connecting said members whereby upon movement of one of said members, anyone major lens may be superposed with any one of said minor lenses, and means serving to disengage said mechanical connection for permitting manual movement of said major lens carrying member independent of said minor lens carrying member.

4. In a device of the class described, a movable member carrying a plurality of minor lenses, another movable member carrying a plurality of major lenses, means mechanically connecting said members'whereby upon movement of one of said members, any one major lens may be superposed ith any one of said minor lenses, means for disengaging said mechanical connection, and means for efiecting manual movement of said major lens carrying member independent of the other member while said mechanical connection is disengaged. I

5. In a device of the class described, a rotatable member carrying a plurality of minor lenses, another journaled member carrying a plurality of major lenses, means mechanically connecting said'members whereby upon manual rotation of one of said members any one major lens may be superposed with any one minor lens, and means for effecting selective manual tllIIIIIl of sald ma or lens carrylng member independent of said minor lens carrying member.

1 6. In a device of the class described, a rotatable member carrying a plurality of minor lenses, another oscillatory member carrying a plurality of major lenses, means mechanically connecting said members whereby upon rotation of one of said members, the other member is automatically rotated so that any one major lens may be superposed with any one minor lens and means for disengaging said mechanical connection when the major lens carrying member is turned to a position in which no major lens is-operatively superposed with a minor lens.

7. In a device of the class described, a casing having an aperture therethrough, a pair of lens holding members mounted within said casing so as to turn about a common axis, one of said members carrying a plurality of major lenses and the other carrying a plurality of minor lenses, means mechanically connecting said members whereby upon rotation of one of said members, any one major lens may be superposed with any one minor lens in registry with said aperture, means operable to disengage said mechanical connection, and means for selectively turning said major lens carrying member independently of the other member while said mechanical connection is disengaged.

8. In an optometer, a rotatable disc carry ing a plurality of spaced lenses of graded powers, a casing within which said disc is enclosed, said casing having an opening with which said lenses are adapted to be successively registered, said disc having an opening adjacent the lens of greatest power and adapt ed to register with the casing opening to form a zero setting, a detent engaging a peripheral portion of said disc, notches in said disc adapted to be engaged by the detent to retain the disc in lens registering positions, the spacing between two notches being greater than the spacing between the others, said greater space being arranged on said periphery so as to pass said detent when the disc opening is coming into registry with the casing opening.

9. In an optometer, a journaled member carrying a plurality of major lenses, another rotatable member carrying a plurality of minor lenses, a casing enclosing said mem bers and having an opening, an intermittent motion mechanical drive interconnecting said members, said drive serving to move the major lens carrying member an angular distance upon the completion of every revolution of the minor lens carrying member, a peripheral portion on said minor lens carrying member, said portion having spaced notches, a detent adapted to engage in said notches for retaining the minor lenses in position to register with said casing'opening, the spacing between notches which passes said detent at the end ofa revolution of the minor lens carrying member being greater than the other spacing for the notches, the other spaces between notches being substantially equal.

10. Ina device of the class described, a pair of casings each having an opening therethrough, means disposedin each casing for bringing difierent lenses in registry with said opening, means for adjusting the pupillary distance between said openings, and a screen associated with each casing and adapted to be moved across said openin each screen having a pinhole for etfectingan exact adjustment of the pupillary distance.

11.=In a device of the class described, a casing having an opening therethrough, means disposed within the casing for bringing different lenses into registry with said opening, a screen movably disposed on said casing, said screen having a pin hole and anonapertured portion whereby by movement of the screen, the opening may be entirely carried by said member and adapted to be successively registered ivitli the opening,

means for rotatingsaid lenseswhen in regis-V try with said opening, and means for simultanecusly rotating said tube'and pointer in unison with a registered lens.

13. In a device of the class described, a easing :having an opening, a member rotatably mounted within said casing and a plurality of minor spherical lenses of i'inely graded powers, another oscillatable member disposed within the casing and carrying a plurality of major spherical lenses of coarsely graded positive and negative'powers, a mechanical connection between said members whereby the :major lens carrying member is moved an angular distance to bring a new majorlens'into registry vith the casing opening upon completion of each revolution of :the minor lens carrying member, and means for selectively oscillating'thcmajor lens car-- rying member to secure an approximate positive or negative refractive power without rotation of the minor lens carrying member.

14. In a device of theclass described, a movable member carrying a plurality of minor lenses, another movable member carrying a plurality of major lenses, means mechanically connecting said members whereby upon movementof one of said members, any one major lens can be superposed with any one minor lens, a member manually movable to either one 01 two positions, and means co operably associated with said member for disrupting said mechanical connection when,

said manually movable member is in one of said positions and to establish said connection when moved to theother of said two positions.

15. In an optometer, a casing having a sight opening, a plurality-of major lenses disposed within the casing, a' plurality of minor lenses also disposed within the casing, a member movable for successively registering said major lenses with said opening, a second member movable for successively registering said minor lenses with said opening, mechanical motion transmitting means interconnecting said members for causing intermittent movement of said first member upon movement of said second member, and means for effecting movement of said first member independently of said second member.

16. In'an optometer, a casing having a sight opening, a plurality of major lenses disposed within the casing, said lenses being of graded powers and being in positive and negative groups, a .pluralityofminor lenses also disposed within the casing, a member movable for successively registering said major lenses with said opening, said positive lenses bein registered with theopening -for;,=

aportion OI the extent of travel'of said member and said negative lenses being registered for another portion of the extent of travel of said member, a second member movable for successively registeringsaid minor lenses Wltll said opening, mechanical motion transbefore another'maj or lens is registered with the opening, and means for effecting quick shifting movement ofsaid first member from said first portion of its travel to said second portion independently of said secondmember.

17. In an optometer, a casing, a plurality of lenses disposed within thecasing, saidcas- .lngihaving an opening, means for effecting desired combinations of lenses/in registry with said opening, a screen movably disposed within the casing, and a lever operably connected to the screen and extending exteriorly of the casing. Y o

18. In an optometer, a casing having front and back plates,the back plate being adapted for positioning near the eye of a patient, said casing ha-vinga sight opening therethrough,

a plurality of lenses within the casing, meansfor effecting desired combinations-of lenses in registry with said sight opening, a screen movably mounted on the casing in close proximity to said back plate, said screen having an opening of size-comparable to said sight opening and also a-pinhole opening, and iiieansformoving said screen whereby either the opening in the same or the pin hole can be registered with sa d sight opening.

19. In an optometer, a casing having front andback plates, the back plate being adapted v-for positioning. near't-he eye of a patient, said casing havin a sight opening therethrough, a plurahty otlenses within the casing, means for effecting desired combinations of lenses in registry with said sight opening, a screen movably mounted .on the casing in close proximity'to said back plate, said screen having an opening of size comparable to said sight opening and also a pin hole opening, the inner face of said back plate having recess to receive said screen, and means for moving said screen whereby either the opening in the same or said pin hole can be registered with said opening.v

20. In an optometer, a movable member carrying a plurality'o-i minor lenses, another movable member carrying a plurality' of major lenses, means mechanically connecting said members whereby upon movement of one of said members any one of a. number of major. lenses can be superposed with any one of said minor lenses, and means operative upon movement of one of said members be yond a certain amount in one direction for effecting disengagement of said mechanical connection.

21. In an optometer, a movable member carrying a plurality of minor lenses, another movable member carrying a plurality of major lenses, means mechanically connecting said members whereby upon movement of one of said members any one of a number of major lens can be superposed with any one of said minor lenses, and cam .means automaticallyoperative upon movement-or" one of said members beyond a certain amount in one direction for effecting disengagement of said mechanical connection.

22. In an optometer, a movable member carrying a plurality of minor lenses, another movable member carrying a plurality of major lenses, means mechanically connecting said members whereby upon movement of one of said members any one of a number of major lenses can be superposed with any one of said minor lenses, means including a bar movably connected to said major lens carrying member and movable to one position for disengaging said mechanical connection and to another position for establishing said connection, and means for moving said bar to said one position upon moving said major lens carrying member beyond a certain amount in one direction.

23. In an optometer, acasing, a pair of rotatable lens carrying discs positioned Within the casing, a locking bar slidably carried by one of said discs, motion transmitting mechanism connecting said discs, said mechanism being disrupted for one position of said bar and operable for another position of said bar, and cam means for moving said bar tosaid one position responsive to rotation of said one disc beyond a certain amount in one direction.

24. In a device of the class described, a member having a sight opening, means carrying a plurality graded lenses adapted to successively register a lens with said opening, anauxiliarv lens, and means for detachably se 'uring said auxiliary lens to said member iirregi try With said opening, said means being engageable upon relative rotation between said auxiliary lens and said member.

' 25. In a device of the class described, a member having a sight opening, means carrying a plurality of graded lenses positioned on one side of said member and adapted to suecessively register a lens with said opening, an auxiliary lens, a mounting for said auxiliary lens, and means for detachably securing said mounting to the otherside of said member with the auxiliary lens in registry Withsaid opening, said means including a tab projecting fromthe mounting, and a projecting portion secured to said member cngageable with said tab upon axial rotation of the mounting relative to said member.

26. In a device of the class described, a member having a sight opening, means carrying a plurality of graded cylindrical lenses disposed on one side of said member, means for bringing said lenses into successive registry with said opening, and means for effect ing axial rotation of an individual lens in registry with said opening without rotating certain others of said lenses not in registery With said opening, said last mentioned means including a gear journaled to said member, a gear segment connected to said gear, a pinion journaled to said member and cooperably engaging said segment, and means for efiecting' manual rotation of said pinion.

27. In a device of the class described, a member having a sight opening, means carrying a plurality of graded cylindrical lenses disposed in one side of said member, means including a manually operable knob ournaled on the other side of said member for bringing said lenses into successive registry With said opening, and means including another manually operable knob journaled adjacent to said first knob for effecting axial rotation of a lens in registry with said opening Without rotating certain others of said lenses not in registry With said opening.

In testimony whereof, I have hereunto set my hand. CLYDE L. HUNSICKER. 

